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Vanadium Pentoxide Extraction And Nitriding Process

Posted on:2010-03-28Degree:MasterType:Thesis
Country:ChinaCandidate:X WangFull Text:PDF
GTID:2191360278969360Subject:Electrochemical Engineering
Abstract/Summary:PDF Full Text Request
Vanadium is a "modern industrial monosodium glutamate" is the development of modern industry,modern science and technology of modern national defense and essential materials.Vanadium is an important strategic resource,has a broad application prospects.China is a big country vanadium resources,mainly vanadium V(Ⅲ) and V(Ⅳ) occur in the form of stone coal,the traditional method of using sodium chloride roasting stone coal extracted from vanadium pentoxide,this process with a large quantity of emissions harmful gases Cl2 and HCl, serious pollution of the environment,while vanadium recovery rate of less than 50 percent,and the study of a new technology to replace the traditional process,reduce pollution and improve the utilization rate of resources is of great significance.In the literature available on the basis of this paper a stone coal mine in guangxi to the characteristics of oxidation roasting-acid leaching-extraction,identified oxidation roasting-acid leaching process in the best conditions:Microwave calcination temperature700℃,additives for the 6%Na2CO3,roasting time 2h,leaching time 7h,leaching temperature of 85℃,oxidation agent for the 3%MnO2,sulfuric acid dosage 30mL/100g stone coal,liquid-solid ratio of 1:1,vanadium leaching rate of 83%.Leaching solution using 10%P204+90%kerosene as an extraction agent,the seven countercurrent extraction,extraction 7 minutes in each grade,O:A=1:1,vanadium extraction rate could reach more than 95%.Extract of the O:A=10:1 conditions,the 3.0mol/LH2SO4 solution three stripping,each class 15 minutes,vanadium stripping rate of 99.11 percent.Stripping oxidation of the sodium chlorate,ammonia regulation pH to 2 around the 95℃for 3h,received more precipitation red vanadium ammonium,and more vanadium ammonium perchlorate at 550℃in muffle furnace under roasting 2h,can be obtained in line with the Chinese standards vanadium pentoxide.At the same time,the current increase in China's vanadium plant, lower prices and raise the price of vanadium is particularly important, given the V-80%~90%for iron and steel additive,and vanadium nitride as the most important additives.Vanadium nitride can be synthesized by microwave processing of the precursor of V2O5(or ammonium metavanadate) and carbon black in N2 atmosphere.In the present work,we investigated the effects of the ratio of the carbon black,temperature,time,flux of N2,compacted density,additives etc.for the amount of the nitrogen in the process.It showed that the pressure of the compound pressing is 20MPa,the ratio of carbon black is 35%,the deoxidization time is 60 minutes,the deoxidization highest temperature is 933K,the nitrification time is 120 minutes,the nitrification temperature is 1723K,the flux of N2 is 2L/min.The amount of the nitrogen and vanadium in the product are 12.6%,79.2%respectively with density of 6.5g/cm3.The product is tested by XRD method and we compared the previous process with the traditional resistor thermal process.It is found that the process we used not only shorten the time of reaction and cooling but also save the energy,simplify the process and reduce the cost.
Keywords/Search Tags:Stone coal, leaching, extraction, vanadium pentoxide, nitrogen
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